Jean Todt insists he is not moved by claims extreme diets are putting drivers at risk.
As the heavier 2014 cars struggle to get beneath the 692kg minimum weight limit, rumours of drivers deliberately dehydrating, fasting and even fainting have been swirling in the paddock.
"I did a diet this winter but you get to certain limits that the body can no longer take," he said, clearly urging for an increase in the weight limit.
But Todt, the president of the FIA, said it is up to the drivers to manage their weight loss in a healthy way within the existing rules.
"Honestly, I don't know why a driver ... I think normally you can do a good diet and not have to go to hospital because you have been losing some kilos," he is quoted by the Telegraph.